> so wouldn't you accomplish HA without the pseudocontroller by just putting both pods in the Service?

I'm not sure how fast that would be, the extra controller container is needed for the almost instant failover.

Answering your second question, why not an init container in the secondary, because now we can scale that failover controller up over multiple nodes, if the node where the (fairly stateless) controller runs goes down, we'd still have to wait until k8s schedules another pod instead of almost instantly.